Sebastian Vettel posted the fastest time in the third practice session at the Belgian Grand Prix ahead of qualifying later Saturday.
The three-time defending Formula One champion beat Fernando Alonso's time late in the session to clock a best of 1 minute, 48.327 seconds, putting him .105 clear of the Spaniard and .206 ahead of Red Bull teammate Mark Webber.
Lewis Hamilton again struggled in his Mercedes and finished 12th. In the afternoon, the British driver bids for his fourth consecutive pole position. Vettel's last pole was four races ago, at the Canadian GP.
Toro Rosso driver Jean-Eric Vergne showed good form to finish fourth in mostly dry and overcast conditions.
In Friday's second practice, both Vettel and Alonso sustained punctures to their rear-right tires, putting the spotlight back onto manufacturer Pirelli.